1. Field
The present disclosure relates to a large scale concrete girder and its manufacturing method, and more particularly, to a large scale concrete girder manufactured by using an Ultra High Performance Concrete (UHPC) beam as a form and a structural member and its manufacturing method.
2. Description of the Related Art
When a concrete girder is manufactured by casting concrete, forms made of plates are respectively installed at end surfaces in the longitudinal direction of the concrete girder, traverse side surfaces, and a bottom surface. A form is a member which is used only for containing concrete to form a concrete girder. The form is a temporary member which will be dissembled and removed after the concrete is completely cured.
In case of making a large scale concrete girder, a placing pressure of concrete applied to the form also increases. Therefore, in order to prevent the form from deforming, a support member for preventing the increase of thickness of the form or the deformation of the form should be installed. In order to prevent deformation of the form, the form is made of steel. Accordingly, the weight of the form increases, which gives great difficulty in handling the form and also greatly increases costs for making the form.
In addition, in case of making a large scale concrete girder, in order to meet the design strength of the concrete girder, a large amount of reinforcing bars or tendons should be placed in the concrete. If a large amount of tendons are disposed or if the tensile force of the tendons is increased, a great bearing pressure is applied to both longitudinal ends of the concrete girder due to the settlement of the tendons, which increases the possibility of bearing failure.